• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.713-719
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• 2011

The antioxidant activities of the ethanol extract of Arctium lappa were assessed by measuring the 1,1-diphenyl-2-picrylhydrazyl( DPPH) radical scavenging effect, inhibition of $Fe^{2+}$-induced lipid peroxidation, inhibition of malondialdehyde(MDA)-bovine serum albumin(BSA) conjugation reaction and antimutagenic capacities using the Ames test. The DPPH radical scavenging activity and inhibition of $Fe^{2+}$-induced lipid peroxidation of the $Arctium$ $lappa$ ethanol extract significantly increased in a dose-dependent manner. In the radical scavenging assay using DPPH, the $IC_{50}$ of the Arctium lappa extract was 296 ${\mu}g$/assay(1.29 mg of dry sample). In addition, the $IC_{50}$ in the inhibition of $Fe^{2+}$-induced lipid peroxidation was 1,759 ${\mu}g$/assay(7.65 mg of dry sample). This extract also significantly inhibited the MDA-BSA conjugation reaction with an $IC_{50}$ of 57.58 mg/assay(250 mg of dry sample). However, no inhibitory effects against the direct and indirect mutagenicities in $Salmonella$ Typhimurium TA98 and TA100 were observed. Based on these results, the ethanol extract of $Arctium$ $lappa$ was shown to display considerable antioxidative activities.

• Natural Product Sciences
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• v.9 no.2
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• pp.80-82
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• 2003

Since reactive oxygen radicals play an important role in carcinogenesis and other human diseases including neurodegenerative states, antioxidants present in natural products have received considerable attention for alleviation of these disease states. Therefore, in order io identify antioxidants in plant extracts, fifty-seven methanolic extracts derided from indigenous Korean plants were primarily assessed for potential to scavenge stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. As a result, nine plant extracts were found to exhibit the DPPH free radical scavenging activity in the criteria of $IC_{50}<40\;{\mu}g/ml$. In particular, the extracts of Melioma oldhami $(IC_{50}=0.1\;{\mu}g/ml)$, Myrica rubra $(IC_{50}=16.2\;{\mu}g/ml)$, Sympolocos paniculata $(IC_{50}=23.0\;{\mu}g/ml)$, Carpinus laxiflora $(IC_{50}=25.1\;{\mu}g/ml)$, and Cleyera japonica $(IC_{50}=26.2\;{\mu}g/ml)$ showed a potent radical scavenging activity. Further study for the identification of active compounds from these lead extracts might be warranted.

• Journal of Life Science
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• v.28 no.8
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• pp.900-907
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• 2018

This study was carried out to evaluate the possibility of unripe apple peel water extracts as cosmetic materials and to evaluate the biological activities of the antioxidant and whitening effects of the samples. The antioxidative properties of the samples were confirmed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) cation radical scavenging ability. To evaluate the whitening effect of the samples, several analytical techniques were used, including toxicity evaluations of the samples by MTT assays. Measurements of the inhibition rates of cellular tyrosinase, melanin synthesis rates, and expression rates of whitening-related proteins and genes were confirmed using melanoma (B16F10 cell). At equivalent unripe apple peel water concentrations ($1,000{\mu}g/ml$), the DPPH radical scavenging and the ABTS cation radical scavenging activities were 77.3% and 93.1%, respectively. The whitening activity evaluation showed that tyrosinase activity and melanin synthesis were inhibited by 19.8% and 17.3%, respectively, at unripe apple peel water extract concentrations of $50{\mu}g/ml$. In B16F10 cells induced by ${\alpha}$-MSH, the expression of tyrosinase, TRP-1, and TRP-2 decreased. Also, the activity of the transcription factor MITF was inhibited. In real-time PCR experiments, the expression of related genes at the upstream signal level was also found to be progressively lowered as the concentration of unripe apple peel water extracts increased. From these results, it was confirmed that the unripe apple peel water extracts showed excellent whitening efficacy and could be used as safe, natural, raw cosmetic material in the future.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.3
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• pp.104-110
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• 2008

Objectives : This experiment study was performed to investigate the anti-inflammation and anti-oxidant effects of Indigo Naturalis(IN) and Rehmanniae Radix(RR) which were herbs for clearing heat. Methods : Anti-inflammation and anti-oxidation effects of IN and RR that were measured by the inhibitory ability of Nitric oxide(NO) production and the scavenging for 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical. Results : 1. IN and RR groups were not showed cell toxicity. 2. In the inhibitory ability of NO production, IN groups were better than RR groups, but there were no statistical significances among the groups. 3. In the scavenging for DPPH radical, IN groups were better than RR groups, but there were no statistical significances among the groups. Conclusions : These results showed that the IN group was better than the RR group in treating skin eruptions, especially those such as erythema, purple spot, papule, pustules which appear in acute inflammation.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.412-417
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• 2009

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on DPPH (1,1-diphenyl- 2-picrylhydrazyl), a total extract of the twigs of Vitex rotundifolia (Verbenaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of three iridoid compounds, 10-O-vanilloylaucubin (1), 10-O-p-hydroxybenzoylaucubin (2) and aucubin (3), two C-glycoside flavones, vitexin (4) and orientin (5), and a quinic acid derivative, 3,4-di-O-caffeoylquinic acid (6). Their structures were elucidated by spectroscopic studies. Among them, compounds 5 and 6 showed the significant antioxidative effects on DPPH free radical scavenging test. In riboflavin-NBT-light and xanthine-NBT-xanthine oxidase systems, compounds 5 and 6 exhibited the formation of the blue formazan in a dose-dependent manner. Compounds 5 and 6 showed better superoxide quenching activities than vitamin C.

• Journal of Pharmacopuncture
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• v.12 no.3
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• pp.73-79
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• 2009

Objectives : This study was performed to investigate the anti-inflammatory and anti-oxidantic effects of GaeYongHwan(GYH) extract which has been used for patients with acnes. Methods : Anti-inflammatory and anti-oxidantic effects of GYH extract were tested in terms of inhibitory ability of Nitric oxide(NO) production, 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity and anti-bacterial effects against Propionibacterium acnes(P. acnes). Results : 1. All GYH treated groups did not show cytotoxicity. 2. Treatment with $100{\mu}g/m{\ell}$ of GYH extract lowered production levels of NO significantly compared to non-treated control or normal. 3. All of GYH treated groups did not show DPPH free radical scavenging activities. 4. All of GYH treated groups did not show anti-baterial action against P. acnes. Conclusions : These results imply that GYH extract has anti-inflammatory effect to treat acnes.

• Preventive Nutrition and Food Science
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• v.11 no.3
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• pp.198-203
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• 2006

The flowers of Chrysanthemum morifolium (Compositae) were investigated for their biofunctional components. Antioxidant compounds were identified from the flower of Chrysanthemum morifolium, through activity-guided fractionation and repeated column chromatographic separations. The structures of the isolated compounds were characterized as chlorogenic acid (1), luteolin (2) and quercitrin (3) by the analysis of physico-chemical and spectral data. Their antioxidant effects were evaluated by assaying for 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity and inhibition of xanthine/xanthine oxidase activity.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.223-227
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• 1996

The antioxidant activity of Ecklonia stolonifera was determined by measuring lipid peroxide produced when a mouse liver homogenate was exposed to the air at $37^{\circ}C$ using 2-thiobarbituric acid (TBA) and the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The methanol extract of Ecklonia stolonifera showed strong antioxidant activity. And the methanol extract was fractionated with several solvents. With regard their fractions, the antioxidative activity were in the order of ethyl acetate>dichloromethane insoluble intermediated phase>dichloromethane>n-butanol>water fraction. The ethyl acetate soluble fraction exhibiting the strongest antioxidant activity was further purified by repeated silica gel and Sephadex LH-20 column chromatography. Antioxidant phloroglucinol was isolated and identified by$ ^1H-NMR\; and\; ^{13}C-NMR$. Its antioxidant activity was simlilar to that of L-ascorbic acid.

• Preventive Nutrition and Food Science
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• v.19 no.1
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• pp.27-33
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• 2014

Hydrolysates of Trianthema portulacastrum in acidified methanol were evaluated for their total phenolic (TP) constituents and respective antioxidant activities using in vitro assays (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, percent inhibition of linoleic acid peroxidation, and ferric reducing power). The observed results indicate that root, shoot, and leaf fractions of T. portulacastrum contain 50.75~98.09 mg gallic acid equivalents/g dry weight of TP. In addition, these fractions have substantial reducing potentials (0.10~0.59), abilities to inhibit peroxidation (43.26~89.98%), and DPPH radical scavenging capabilities ($6.98{\sim}311.61{\mu}g/mL$ $IC_{50}$). The experimental data not only reveal T. portulacastrum as potential source of valuable antioxidants, but also indicate that acidified methanol may be an ideal choice for the enhanced recovery of phenolic compounds with retained biological potential for the food and pharmaceutical industry.

• Journal of the Korean Wood Science and Technology
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• v.32 no.6
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• pp.43-49
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• 2004

Three flavonoids, quercetin, taxifolin, and kaempferol were isolated from the woods of Liriodendron tulipifera. Their structures were determined by spectral analysis. Based on 1, l-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method, the antioxidative activities of three isolated compounds and their acetates were measured in order to search for natural antioxidants. The IC₅₀ of quercetin (1), taxifolin (2), and kaempferol (3) were 3.6, 3.9, and 4.1 ㎍/㎖, respectively.